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Exhaust leak...possibly intermittent

Is there any condition that would make a Ford Escape have an intermittent exhaust leak that could come into the cab?

An intermittent exhaust leak is highly improbable. What issues make you suspect you have an intermittent leak?

Don’t let this one slide. Leaking exhaust can be deadly.

Could you be smelling oil seeping past old valvecover gaskets and burning on the exhaust?
Exhausts don’t leak intermittantly, but weepage occasionally dripping on an exhaust is common.

There is some kind of odorless gas that has made me intoxicated while driving…I know it sounds weird but no one can find a leak. Autozone said it might be because of an exhaust gas recirculation valve…is that possible? I really need help on this one…I am afraid to drive it and don’t feel ok selling it either. It isn’t just me that it has affected but I have had the most problems.

Should I replace the entire emissions and exhaust system?

@lesshadow, have a shop hook up the evap/smoke machine to the tailpipe and allow enough time to fill up the entire system from rear to front.

Look for smoke exiting from leaking gaskets or joints.

You might have a cracked exhaust manifold or a deteriorated manifold flange gasket, etc.

Just for kicks and giggles, is the check engine light on?

Are you sure it’s not raw fuel you’re smelling? Maybe you have an injector that’s leaking externally.
Wasn’t this scenario mentioned on the show recently?

I hit mailboxes and ended up staggering and not being able to talk, friends thought I was drinking, cop made me blow into tube, ended up in hospital…no engine light no fuel smell. Affected another friend as well. Not as severe.

Three shops could not find leak…and said there was no soot…and used a machine on the tailpipe. I am not mechanical. I know some about minor things. Was going to have my brother look at it but he isn’t a mechanic either. Don’t want to sell it to anyone…am afraid to drive it myself.

@lesshadow, do you also get woozy if your ac is in recirc mode?

By the way, why is the post called intermittent exhaust leak if the problem is consistently so bad that you don’t want to drive the truck?
It sounds as if the problem is permanent, not intermittent.

I thought of one possibility: If either the tail gate or the back window is not closed all the way, exhaust fumes can be sucked into the cabin by the partial vacuum created as you move along. Be sure after opening the tail gate or rear window, that you are closing them all the way.

db, I am not sure about the recirculation mode. I don’t know if it is an intermittent leak or not…I figured that maybe it was because no one could find a leak. I really don’t know much about cars…except how to drive them. The back gate and window are closed. I just don’t have any clue what to do next.

I think it was on outside intake when it happened. Not totally sure.

To follow up on what db suggests, be sure not to run the heating system on recirculate. Back in the late 1930s, an engineer named Nils Erik Walberg who worked for the Nash motor company did wind tunnel tests. He found that when the car is in motion, the pressure outside the car is greater than the inside pressure and hence let the outside air creep into the cabin. By inducting outside air at the windshield level, he could pressure the system. Heating this air kept the car much warmer than cars that had a recirculating heater. His system, which Nash marketed as “Weather Eye” heating and ventilation was adopted by all the manufacturers by the 1950s. Prior to Walberg’s system. cars had a box that hung down under the dashboard that was a small radiator and fan that just recirculated the interior air. At any rate, run your Escape system on outside air mode and run the blower at a speed higher than the lowest and see if this solves your problem.

@lesshadow, does your exhaust sound perfectly fine?

No hissing or clicking noises?
No rumbling?
No missing hardware for the exhaust manifolds (especially the one near the firewall)?

An odorless fume that makes you woozy and feel intoxicated can only be one thing…carbon monoxide is entering the passenger cabin. And this is very, very damgerous.

No, it is not the EGR system. The EGR system cycles a small portion of the exhaust fumes back into the engine’s intake to keep the cylinders from getting too hot inside (the expended fumes displace a bit of the oxygen, causing the fire to burn not-as-hot). The EGR system only does this intermitttantly under very specific conditions, and the EGR system does NOT vent them into the air, but rather to the engine’s intake.

Most shops should have a device that senses and measures hydrocarbon emissions. It’s generally used to perform emissions outputs on pre-1996 cars, and in some states other categories of cars such as custom hotrods or whatever. These sensors should be able to detect exhaust leaks. If not, and it were my vehicle, I’d (1) dismantle the system if necessary, and (2) get a carbon monoxide sensor for the car’s cabin. You should be able to get a CO sensor cheap at the hardware store.

Best of luck with this.

There is some clicking in the motor area and it had become somewhat sluggish…I don’t know if that could be relevant or not. I got red-faced which is consistent with CO…I don’t know what to do with this car…I owe 17000…any suggestions. Do you think I could trade it in and not owe lots of extra money?

“There is some clicking in the motor area and it had become somewhat sluggish”. I wonder if you have a bad exhaust manifold gasket. The escaping exhaust gas from a small crack in the gasket can make a clicking sound. I remember when I was a kid, my dad had to have an exhaust manifold gasket replaced on a 1949 Dodge and it made this clicking sound.
You may want to purchase a carbon monoxide detector. I had to replace the CO detector in our house because it decided to beep about every 30 seconds in the middle of the night. Replacement batteries didn’t solve the problem. The label on the back said that the detector was only good for 7 years and when its life was over, it would do the 30 second beep. The replacement I bought for $25 is battery operated and has a display indicating the parts per million of CO present in the air. You can buy one at WalMart. The digital readout will tell you if you have CO present in the cabin of your car and the level.

Sluggish performance could indicate a restricted exhaust which could cause a leak that is overlooked at idle because the pressure is low causing minimal leaking but at cruising speed the pressure might cause a considerable volume of leakage, plus, vacuum at cruising speed would tend to draw the exhaust into the cab. Has anyone checked for back pressure in the exhaust system?

Now that I post, I see that Triedag is ahead of me as usual. I type the Biblical method, seek and ye shall find.


What was the problem with your toxic odorless fumes?

I think I have the same problem and want to fix.